Electric fuse device



Aug. 23, 1938. HERMANN 2,128,145

ELECTRIC FUSE DEVICE Filed June 13, 1936 1: i W Ml Irwverwtor. Benjamin F2.Hermann,

ttorneg.

Patented Aug. 23, 1938 UNITED STATES ELECTRIC FUSE DEVICE Benjamin It. Hermann,

signer to General Elect ration of New York Lanesboro, Man, as.- ric Company, a corpo- Application June 13, 1936, Serial No. 85,062

8 Claims.

'Ihe present invention relates to electric fuse devices and has for an important object the provision of improvements in fuse cutouts particularly adapted to be suspended from overhead & electric line conductors, although it is to be understood that the invention is not limited to employment solely with the line suspension type fuse cutouts.

A more specific object of the invention is the provision of improved simple and reliable means 'for giving indication, clearly and readily observable from a distance, of the operation of a fuse cutout. c

Other objects and the details of the invention will become apparent from the following description taken in conjunction with the accompanying. drawing in which Fig. 1 illustrates an exemplary form of a line suspended type fuse cutout embodying the present invention, Fig. 2 is an enlarged view of the lower end of the fuse cutout as seen from the side of the cutout opposite to that illustrated in Fig. 1 and showing in non-indicating position one form of indicating device embodying the present invention, Fig. 3 is a view similar to that of Fig. 2 but showing the indicating device in indicating position, Fig. 4 illustrates a modified form of indicating device with the indicating arm of the device in non-indicating position, Fig. 5 is further illustrative of the device of Fig. 4 with the 33 indicating arm in indicating position, and Fig. 6 is a detail view of a portion of the mechanism of the device illustrated in Figs. 4 and 5.

Referring to the drawing, it will be seen that the fuse cutout illustrated in Fig. 1 thereof comprises in the main a fuse holder tube to of insulating material such as pressed fibre, a socalled live line clamping device I i for securing the cutout to an overhead electric line conductor and a combined connection and indicating device l2 secured 40 to the lower end of the fuse holder. The main body ll of the clamping device, which is of metal,

has at its lower end a socket portion It for receiving the screw threaded upper end of the fuse holder II. On the upper end of the body l3 and lit 45 offset from the extended axis of the fuse holder is an upwardly projecting shoulder i5 terminating in a lug IS which has a centrally disposed screw threaded opening. A clamping jaw member I1 is pivotally mounted on the shoulder l5 by means of a pin 18 which extends through the shoulder and into engagement with spaced depending flanges I! formed on the clamping member and arranged to straddle the shoulder. The inner surface of e a ping Jaw member has a recess 20 formed 56 therein to cooperate with a shoulder 2i formed on body I: to grip therebetween an electric line conductor 22. The clamping law has also a finger 22' projecting outwardly and provided with a downwardly facing guide surface 23, and body I; has a tapered flange 24 formed thereon'in a man- 6 ner to provide a guide surface 25. These two guide surfaces are arranged to converge toward the wire gripping surfacesprovided by the recess 20 and the shoulder 2| to guide the line conductor 22 into engagement therewith and thereby faclll0 itate installation of the cutout on the line conductor. In order toeffect clamping of the line conductor between the clamping jaw 11 and the body ll, an adjusting screw 26 is provided supported in the screwthreaded opening of lug Ii 16 and passing loosely throughan opening provided in a projection 21 formed on the. clamping jaw at the opposite sideof pivot ll from the gripping recess 20. Screw 25 has at its upper end a flange head 28 which engagesa bearing boss formed on the upper surface of projection 21 and has also a shoulder 26' arr'angedto bear against the lower surface of projection. This screw is provided at its other end with an eye portion lil into which. may be inserted the pinof acommon form of 2! switch stick (not shown) for supporting the fuse cutout during installation thereof on the conductor 22 and for turning. of the screw to eifect clamping of the conductor between the clamping jaw i1 and the body l3. When the screw 28 is 30 turned to effect clamping of the conductor between the jaw I1 and the body 13, shoulder It. presses upwardly against projection 21 to cause clamping jaw l1 to rotatein a clockwise direction (as viewed in Fig. 1) about itspivot it thereby to 3| force gripping recess Zl'downwardly on to the line conductor 22 so as to clamp the conductor between the recess 20 and the shoulder 21.

The combined connection and indicating device I! has a body portion'in the form of a. ferrule 3| 40 provided with an opening" for accommodating the lower end of fuse holder tube it, the ferrule being secured to the holder in any suitable manner as for example by means of a pin 33 extending through openings in the ferrule into engagement with the holder. Ferrule II has a projection 34 on one side thereof formed with a flat contact surface 35 as best shown in Figs. 2' and 3, and also with a lug portion 3 6. best shown in Fig. 1, provided with a centrally disposed screw threaded opening for the accommodation of clamping bolt 31. Projection 34 is adapted to have secured in engagement with its flat. contact surface ii an electric conductor 88, which may be a transformer lead or the like, by means of a clamping plate ll which may be tightened down on the conductor by means of the clamping bolt 31.

Ferrule 3| has projecting outwardly from the other side thereof an arm 4|! which has formed integrally therewith an arm 4| extending downwardly at an acute angle to the transverse or horizontal axis of the ferrule. Pivotally mounted on the lower end of the arm 4| by means of a pin 42 is an indicator arm 43 which is arranged to swing from a non-indicating position, in which it is disposed substantially at right angles to the axis of the fuse holder tube III, as shown in Figs. 1 and 2, to an indicating position wherein the arm hangs vertically downward as shown in Fig. 3. A hemispherically shaped head 44 is formed at the free end of the indicator arm, which head, due to the additional weight provided thereby, serves under the influence of gravity to bias the indicator arm to swing to its vertical or indicating position. In addition to its biasing function the head 44 serves also to make readily observable the position of the arm by an observer stationed at a relatively great distance and at any angle to the fuse cutout device.

In the embodiment illustrated, the fuse is of the expulsion type and the fuse holder III, the

lower end of which is open, is arranged to accommodate a so-called cable type fuse link which has a flexible extension cable 45 arranged to protrude from the lower open end of the fuse holder, the upper end of the fuse link being anchored in the fuse holder in any well known manner. In the practice of the present invention, the protruding end of the cable extension 45 is passed behind a downwardly projecting finger 46 formed on the projection 40 of the ferrule 3|, thence through a notch formed between the finger 46 and a similar finger 41, and then is securely clamped to projection 40 by means of the winged clamping bolt 48 as shown in Fig. 2. Intermediate the lower end of the fuse holder and the finger 46, the extension cable is arranged to pass under a'pin 43 formed integral with and projecting outwardly from the indicator arm 43. Finger 46 serves to prevent the flexible cable from slipping off of the pin 43. By means of the clamping bolt 43 the cable extension is maintained partially taut so that it engages pin 43 to hold or latch the indicator arm in its substantially horizontal non-indicating position so long as the fuse link within the fuse holder Ill remains intact.

As will be seen best from Fig. 1, indicator arm 43 when in its non-indicating position is relatively inconspicuous due to the fact that it extends horizontally in close side by side relationship with the ferrule 3| and its two projecting arms 34 and 43. Upon operation of the fuse cutout device due to overload and the like, extension cable 45 is released by rupture of the fuse link within the fuse holder l3 and the indicator arm 43, additionally weighted as previously pointed out by means of the head 44, immediately swings downward to its indicating position illustrated in Fig. 3. Due to the weight of the indicator arm and the engagement of pin 43 with the flexible cable extension, the indicator arm acts in aid of the expulsion action of the fuse to pull the fuse link cable extension downwardly whereby a more speedy separation of the parted ends of the ruptured fuse link and extinguishing of the are drawn therebetween is insured. when the indicator arm 43 hangs downwardly in'its indicating position, the weighted hemispherical head 44 is readily observable from relatively great distances and from any angle with respect to the fuse cutout. As will be seen from the foregoing discussion, the indicator of the present invention is simple and sturdy of construction, positive in operation, readily visible and not subject to injurious burning by are gases discharged from the lower end of the fuse holder. A further advantage of the device is that it makes possible the anchoring of the protruding end of the fuse link cable so that upon operation of the fuse the cable is not discharged into nearby live parts of electric apparatus ,or allowed to drop to the ground where in its hot condition it might ignite dry grasses and the like to start a fire. Furthermore, the indicating device is always reliable in its operation since there are no current carrying spring operating parts which may lose their temper and become unreliable in the case of overcurrents.

In the modified form of indicating device illustrated in Figs. 4 and 5, the indicator is in the form of a light weight semaphore arm 50 which may be colored in any desired manner to render it most conspicuous. This indicator arm is hingedly mounted on bosses 5| extending outwardly from opposite sides of a ferrule 52 secured to the lower end of the fuse holder tube III, the arm being carried by a bent wire frame or hinge device 53 the details of which are best shown in Fig. 6. Two loops 54 are formed respectively in opposite sides of the hinge device for securing the same to the bosses 5| by means of screw bolts 55 which are adjusted so as to provide for easy pivoting of the hinge device on the bosses. The hinge device has also two arms 56 and 51 arrangedto project upwardly and lying in a plane at an angle to the plane of the U-shaped stirrup portion 53 of the hinge device. Arm 56 is bent to provide an-elongated loop 59 which serves for the attachment of the semaphore arm thereto by means of rivets 6D. The other arm 51 is bent to provide a loop 6| for the attachment thereto of one end of a tension spring 62, the other end of which spring is attached to a lug 63 formed on an arm 64 projecting outwardly to oneside of the ferrule 52.

At the side of the ferrule 52 opposite to the arm 64 is provided a projection 34 similar to that carried by the ferrule 3| of the first embodiment described and illustrated in Figs. 1, 2,

and 3. This arm 34, as previously pointed out, serves for the connection thereto of an electric conductor 38, such as a transformer lead, by means of a clamping plate 33 and a clamping bolt 31. v

As set forth with respect to the embodiment illustrated in Fig. 1, the fuse holder I0 is adapted to accommodate a cable type fuse link the upper end of which is anchored in the fuse holder in any suitable manner and the lower end of which is provided with a flexible cable extension 45 a portion of which protrudes from the lower open end of the fuse holder tube. In practice, the cable extension is passed under the wire stirrup 53 of the hinge device 53 and securely anchored to the projection 64 by means of wing bolt 65, and the cable extension is maintained under sufficient tension so that it engages the wire stirrup 53 to hold or latch it in its .uppermost position. Under these conditions the arm 56 of the hinge device projects vertically upward and maintains the semaphore indicating arm 53 in its non-indicating position wherein it extends vertically up ward substantially parallel and alongside the fuse holder tube II where it is in its least conspicuous position. Spring 62 in this case is maintained under tension between the arm 51 and the lug 63 so that it tends to move the indicator arm to its indicating position but it is restrained from doing so by the latching action of the cable extension 45 and stirrup 58.

Upon operation of the fuse cutout device due to overload and the like, rupture of the fuse link within fuse holder l releases the cable extension 45 and permits the wire hinge device 53 to be rotated in a clockwise direction, as viewed in Fig. 4, under the influence of spring 62 to swing the indicator arm 50 to a position wherein it is at a substantial angle with respect to the fuse holder tube I ll so that the arm gives a clearly visible indication of the operation of the fuse. The

stirrup 58 of the hinge deviceacts in a mannersimilar to the pin 49 of the first embodiment described to aid the expulsion action of the gases discharged from the lower end of the fuse tube in drawing the fuse link cable extension downwardly, whereby a more speedy separation of the parted ends of the ruptured fuse link and extinguishing of the arc drawn therebetween is insured.

As was the case with the indicator arm of the first embodiment described, the indicator arm 50 of the modified device when in non-indicating position is relatively inconspicuous but upon operation of the fuse cutout swings to an indicating position readily observable from a distance and from any angle with respect to the fuse cutout device. Furthermore, the arrangement of the parts of the combined connecting and indicating device of Figs. 4 and 5 is such that the main current path is through the ferrule 52 and its projecting arms 34 and 64 so that little or no current passes through the spring 62. Hence the spring will not lose its temper due to the passage therethrough of overload currents and will remain reliable in operation under all conditions. In addition to the advantages previously pointed out, the device is simple and sturdy in construction, easy to install and increases the safety of operation of the fuse cutout device due to the firm anchoring of the protruding end of the fuse link cable extension.

What I claim as new and desire to secure by Letters Patent of the United States, is:

1. In an electric cutout, a fuse holder including a fuse holder tube and a terminal member secured to said tube adjacent one end thereof, which said one end has an opening for the outward protrusion of a fuse link extension from said tube, .a clamp carried by said member for fixedly anchoring such protruding fuse link extension to said member, and an indicating device including a semaphore arm pivotally supported by said fuse holder and biased for movement relative to the fuse holder from a first position, wherein said arm extends in relatively close substantially parallel side by side relationship with a part of the fuse holder so as to be relatively inconspicuous, to a second position wherein the arm projects outwardly at a substantial angle to said part of the fuse holder so as to be relatively conspicuous from a distance, said device including an element supported for movement conjointly with said arm and arranged to be engaged by an intermediate portion of a protruding fuse link extension which is anchored to said member by said clamp, thereby normally to impose tension on the fuse link of which said extension forms a part and to hold said arm in its said first position so long as the fuse link is intact.

2. A combined terminal and indicating device for use with a fuse cutout which includes a fuse holder tube adapted to accommodate therein a fuse link having an extension arranged to protrude from an open end of said tube, said device comprising a ferrule adapted to fit around said fuse holder tube adjacent the said open end thereof, a pair of fixed arms projecting outwardly respectively from opposite sides of the ferrule, a clamping device carried by one of said arms for fixedly anchoring to said one arm the extension of a fuse link protruding from said open end of the fuse holder, means carried by the other of said arms for securing thereto an electric lead in current conducting relation with the fuse link extension, a semaphore arm pivotally mounted on said ferrule and biased to swing from a nonindicating position to an indicating position, and an element supported for movement conjointly with said semaphore arm and arranged when the semaphore arm is in non-indicating position to be engaged by a portion of said protruding fuse link extension intermediate the said clamping device and the open end of the fuse holder from which the extension protrudes, thereby to maintain the semaphore arm in non-indicating position when the fuse link is intact.

3. In an electric cutout, a fuse holder including a fuse holder tube and a terminal member secured to said tube adjacent one end thereof, which said one end has an opening for the outward protrusion of a fuse link extension from said tube, a clamp carried by said member for fixedly anchoring such protruding fuse link extension to said member, and an indicating device including a semaphore arm pivotally supported by said fuse holder and biased for movement relative to said member from a first position to a second position to give indication of fuse link rupture, said device including an element supported for movement conjointlywith said arm and arranged to be engaged by an intermediate portion of a protruding fuse link extension which is anchored to said member by said clamp thereby normally to impose tension on the fuse link of which such anchored extension forms a part and to hold said arm in its said first position so long as the fuse link is intact.

4. An article of manufacture for use in a fuse cutout including a fuse holder'tube adapted to accommodate therein a fuse link having an extension arranged to protrude from one end of said tube, comprising a member having an opening for the insertion therein of the said end of the fuse holder tube, means for rigidly securing said member to said tube, clamping means carried by said member for engaging the protruding end of said fuse link extension to maintain the said extension under at least partial tension, means carried by said member for connecting thereto an electric lead in electric conducting relation with said extension, a semaphore arm pivotally mounted on said member and arranged to swing from a non-indicating position to an indicating position, a spring operatively connected for biasing said arm to its indicating position and an element mounted on said member for movement with said arm and arranged to be engaged by said tensioned fuse link extension to said element being arranged to be released upon release of said extension by rupture of said fuse link to permit said spring to move said semaphore arm to its indicating position, said element being operative upon release thereof to pull said extension downwardly.

5. An article of manufacture for use with a fuse cutout which includes a fuse holder tube adapted to accommodate therein a fuse link with an extension of the fuse link protruding from one end of said tube, the said article comprising a ferrule adapted to fit around said tube adjacent the said one end thereof, means for securing an electric lead to said ferrule, a fixed arm projecting outwardly from said ferrule, clamping means carried by said arm for fixedly anchoring thereto a fuse link extension protruding from the said one end of said tube, an element pivotally mounted on said ferrule and having a portion arranged to extend substantially transversely of and adjacent the said one end of said tube to be engaged by the protruding portion of a fuse link extension intermediate the said one end of said tubeand the point at which the extension is anchored to said fixed arm by said clamping means, said pivotally mounted element being arranged to be held in a predetermined position by engagement of such anchored fuse link extension therewith when the fuse link is intact, a spring connected for biasing said element to a second position, and a semaphore arm mounted for movement with said pivotally mounted element, said semaphore arm being arranged to repose in a non-indicating position when said element is held in its said first position by the fuse link extension and to move to an indicating position upon release of saidelement by the fuse link extension upon fuse operation.

6. An article of manufacture for use in a fuse cutout which includes a fuse holder tube adapted to accommodate therein a fuse link with an extension of the fuse link protruding from an open end of said tube, said article comprising a member having an opening for accommodating said tube and adapted to be fastened to the tube adjaoent the said open end thereof, means carried by said ferrule for anchoring thereto a fuse link extension protruding from the said open end of said tube, a substantially U-shaped stirrup element having its opposite legs hingedly mounted on opposite sides of said ferrule with the portion of the stirrup intermediate said legs arranged to extend transversely across the said open end of said tube to be engaged by the anchored protruding fuse link extension, said stirrup element being arranged to be held in one position by engagement of the anchored fuse link extension therewith and being biased to swing to a second position upon release of said extension due to fuse operation, and a semaphore arm mounted for movement in response to movement of saidstirrup element, said semaphore arm being arranged to repose in a non-indicating position when the stirrup element is held in its said first position by said extension and to swing to an indicating position in response to swinging of said stirrup element to its said second position upon release of said extension.

'7. An article of manufacture for use in a fuse cutout including a fuse holder tube adapted to accommodate therein a fuse link having an extension arranged to protrude from one end of said tube, comprising a member having an opening for the insertion therein of the said end of the fuse holder tube, means for rigidly securing said member to said tube, clamping means carried by said member for fixedly anchoring a protruding end of a fuse link extension to said member, means carried by said member for connecting thereto an electric lead in electric conductive relation with said extension, an arm pivotally mounted on said member and arranged to swing from a non-indicating position to an indicating position, an enlarged weighted head at the free end of said arm providing for ready observation of the position of said arm and operative under the influence of gravity for biasing said arm toward its indicating position, and a projection carried by said arm for movement therewith and arranged to be engaged by an intermediate por-- tion of an anchored fuse link extension to maintain said arm in its non-indicating position, said projection being arranged to be released upon release of said extension by rupture of said fuse link to permit said arm to swing under the influence of gravity to its indicating position.

8. An article of manufacture for use with a fuse cutout which includes a fuse holder tube adapted to be mounted substantially vertically and adapted also to accommodate therein a fuse link with an extension of the fuse link protruding from the lower open end of the tube, said article comprising a member having an opening for accommodating said tube and adapted to be secured to the tube adjacent the said lower end thereof, a fixed projection extending outwardly from one side of said member, clamping means on said projection for fixedly anchoring to said projection the extension of a fuse link protruding from the lower end of said tube, a semaphore arm pivotally mounted on said member and arranged to swing from a relatively inconspicuous position wherein the arm is substantially horizontal and in close substantially parallel side by side relationship with said member and said projection to a readily observable position wherein the arm hangs downwardly below said member, and an element carried by said arm arranged to be engaged by an intermediate portion of an anchored extension of a fuse link protruding from the lower end of said tube for holding said arm in its said inconspicuous position, said arm being arranged to swing under the influence of gravity to its said readily observable position upon release of said fuse link extension due to fuse operation.

BENJAMIN R. HERMANN. 

